a) Field of the Invention
The present invention relates generally to a communication card intervening in connections between stations and communication channels, and more particularly to the structure of a jack for use with the communication card.
b) Description of the Related Art
b1) Premise
To carry out communications between two or more computers (e.g., personal computers) or word processors, physical and logical connections must be established between these units by means of wire or radio communication channels, for instance, telephone lines (hereinafter, the physical connection will be referred to as "coupling", whereas circuitry and logical connection indicating a communicable state will be referred to as "connection"). In order to connect the apparatus intending to perform a communication (hereinafter, referred to simply as "station") with the communication channel, a communication controller must be provided which controls the action of transmitting signals from the station to the communication channel and the action of the station receiving signals from the communication channel. Various types of configurations are known as the communication controllers used for this end. The most compact one among them is an IC card incorporating a communication control circuit. Such a type of IC card is called a communication card.
The communication card converts a signal which the station intends to send out to a communication channel (hereinafter referred to simply as "transmission signal", into a format suitable for the communication channel, and converts a signal destined for the station which is supplied through the communication channel (hereinafter, referred to simply as "received signal") into a format suitable for the same station. In the case, for example, where the station is a digital unit and the communication channel is an analogue line, the communication card executes a digital to analogue conversion of the transmission signal and an analogue to digital conversion of the received signal, as well as signal amplification and other processing. Also, in the case, for example, where the station is a personal computer or other unit and the communication channel is a telephone line, the communication card will execute, in addition to the above, processing such as modulation, coding and compression of the transmission signal as well as demodulation, decoding and decompression of the received signal. Among the communication cards a modem card is a card incorporating a modulation/demodulation circuit and hence having modulation and demodulation functions.
As described above, the communication card intervenes between the station and the communication circuit. Accordingly, the communication card must be provided with a member for coupling with the station, and a member for coupling with the communication channel. In the same manner, the station must be provided with a member for coupling with the communication card, and the communication channel must be provided with a member for coupling with the communication card. In the case of, in particular, connecting three parties by wires, that is, the station, the communication card and the communication channel, it is preferable to utilize slot and module type connectors to couple them.
With these type of connections, the slot has a structure in which a member is arranged on the far side of an elongated aperture provided in the casing of the station for electrically coupling with the communication card. On one edge of the communication card, on the other hand, an electric coupling member is arranged corresponding thereto. These electric coupling members are provided in such a manner that when the communication card is sufficiently deeply inserted into the aperture of the slot with that same edge ahead, those electric coupling members are electrically coupled with each other. In this manner, the structure utilizing the slot would realize a electric coupling between the station and the communication card. It is to be appreciated that the slot has a function of receiving and retaining the communication card.
b2) General Constitution of Modular Connector
The modular connector is widely utilized in the case of using telephone lines as the communication channels. The modular connector includes a modular plug and a modular jack corresponding thereto. The modular plug is provided on the communication channel side, and the modular jack is provided on the communication card side. As shown in FIG. 46, by way of example, a modular plug 2 is provided on one end of the cord 21 constituting the communication channel, while a modular jack 3 is provided on one edge 11 having a larger thickness among four edges of the communication card 1. In the following description, that one edge is referred to as integrated connector. Moreover, the communication card 1 (and the slot) is dimensioned in such a manner that the modular jack 3 extends to the exterior from the aperture of the slot with the communication card 1 deeply inserted into the aperture of the slot.
With such a design, the coupling between the modular jack 3 and the modular plug 2 would result in an electrical coupling between the communication channel and the communication card 1. Also, since the communication card 1 is electrically coupled to the station by sufficiently deeply inserting the communication card 1 into the aperture of the slot, the communication channel and the station can be coupled with each other by means of the communication card 1. Under these conditions, when the station calls another station, or when the station receives a call from another station through a communication channel, a connection is established between the station and the communication channel by means of the communication card 1. This will ensure the realization of personal computer communications and the like.
The communication card 1 as shown in FIG. 46 is called a PC card, which is a modem card prescribed by PCMCIA(Personal Computer Memory Card International Association). The PC card ordinarily has a thickness of 5 mm. Due to the necessity of providing the modular jack 3, the thickness of an integrated connector 11 is set at 14 mm greater than the thickness of the other portions. Designated in the diagram by a chain line 4 is a card inserted into the other slot, for example, a memory card. The use of the PC card 1 with the memory card 4 would diversify the communications using PC card 1. For example, it is possible to store into the memory card 4 programs such as data compression and decompression, error detection and correction associated with various communication protocol, or to utilize the memory card 4 to expand the memory capacity of the PC card for the transmission and received signals.
FIGS. 47 to 53 illustrate a general constitution of the modular plug 2 and the modular jack 3. As their basic functions, the modular plug 2 and the modular jack 3 have an electric coupling function, an inserting direction regulation function, an insertion stopping function, and a returning prevention function.
The electric coupling function is implemented by contact pins 23 provided on the tip of a contact pin block 22, and contact wires 31 arranged within the interior of the modular jack 3. The contact pins 23 and the contact wires 31 are both made of electrically conducting materials. Within the interior of the contact pin block 22, the contact pins 23 are electrically coupled to a plurality of (e.g. four) lead wires extending in alignment from the cord 21. As shown in FIG. 50, the contact pins 23 are received in (four in the diagram) grooves 25 excluding the leftmost and rightmost grooves among a predetermined number of (six in the diagram) grooves 25 provided on the tip of the contact pin block 22. As shown in FIGS. 47 and 48, the surface of the contact pin block 22 is provided with a narrow free end 26 presenting a resilience at the base of its neck.
The contact wirings 31 are arranged diagonally and parallel to one another as shown in FIG. 52 within the interior of a socket 32 constituting the modular jack 3. A predetermined number of (six in the diagram) grooves 33 are provided on side walls designated by reference numeral 34 among the side walls of the socket 32, the contact wirings 31 being accommodated in a plurality of (four in the diagram) grooves 33 excluding the rightmost and leftmost grooves among the grooves as shown in FIG. 51. The contact wirings 31 pass through the side walls 34 and extend downward in FIGS. 51 to 53, the extended portion being used for the electric coupling with the circuit within the PC card 1.
When inserting the modular plug 2 into the modular jack 3, the modular plug 2 is inserted into the interior of the modular jack 3 along the direction B of FIG. 52 while depressing the narrow free end 26 in the direction J of FIG. 47. Then, as shown in FIG. 53, the contact pins 23 are brought into contact with the contact wirings 31. This will result in the electrical coupling between the modular plug 2 and the modular jack 3. In other words, the circuit within the PC card 1 is electrically coupled with the communication channel.
The inserting direction regulation function is implemented by the contact pin block 22 and the socket 32. Upon the insertion of modular plug 2 into the interior of the modular jack 3, the contact pin block 22 of the modular plug 2 is guided by the side walls of the socket 32. At that time, the contact pin block 22 and the socket 32 are both dimensioned so that the socket 32 can receive the contact pin block 22 and so that the contact block 22 can not be inserted from other directions or in other orientations. The surface of the contact pin block 22 is provided with the narrow free end 26, and hence the contact pin block 22 is rotationally asymmetrical. Thus, the inserting direction in which the modular plug 2 is inserted into the interior of the modular jack 3 will be regulated in the direction shown in FIG. 52. This allows the user to insert the modular plug 2 into the modular jack 3 constantly in the correct direction.
The insertion stopping function is implemented by a broad fixed end 27 provided at the tip of the modular plug 2 and having a broader width than that of the narrow free end, and a ledge 35 provided on the bottom of the modular jack 3. That is, when inserting the modular plug 2 into the modular jack 3, the broad fixed end 27 comes into contact with the ledge 35, preventing the modular plug 2 from further advancing.
The returning prevention function is implemented by a transition notch 28 extending from the narrow free end 26 sideward, and a retention ridge 36 provided on the side wall of the socket 32 as shown in FIG. 52. More specifically, the user inserts the modular plug 2 into the modular jack 3 along the direction B of FIG. 52 while depressing the narrow free end 26 (using, e.g., fingers) as shown in FIG. 48, and releases the fingers from the narrow free end 26, whereupon the retention ridge 36 comes into engagement with the transition notch 28. Accordingly, even though a force opposite to the direction B of FIG. 52 is applied to the modular plug 2, as long as the force is not too large, the modular plug 2 is not permitted to fall out of the modular jack 3 or to positionally shift to a large extent within the modular jack. When removing the modular plug 2 from the modular jack 3, the modular plug 2 is drawn out in the opposite direction to the direction B of FIG. 52 while depressing the narrow free end 26 as shown in FIG. 48.
In order to couple the PC card 1 with the communication channel by making use of the modular plug 2 and the modular jack 3 having such a structure, it is common practice that, as shown in FIG. 46 the PC card 1 is provided with the integrated connector 11, which is in turn equipped with the modular jack 3. However, such an arrangement of the jack entails some problems. Firstly, the integrated connector 11 protrudes from the slot in the state where the PC card 1 is loaded into the slot, and hence the presence of the integrated connector 11 would obstruct the insertion of, e.g., the memory card 4 into the adjacent slots. Secondly, when moving the station with the modular plug 2 removed from the modular jack 3, the integrated connector 11 will readily collide with external objects (e.g., a desk). Since the integrated connector 11 is thicker than the other portions and hence has a larger mass, the collision of the integrated connector 11 with external objects is apt to cause damage to the PC card 1. Thirdly, the necessity to increase the thickness of the integrated connector 11 compared with the other portions would result in increased production and sales costs, as well as increased complexity of the production processes, increase in material cost, and increase in the space for storing the products.
b3) Improvement in Structure of Modular Connector
To overcome these deficiencies, some improvements are proposed for the structure of the modular jack. One such improvement is a modular jack 3A shown in FIGS. 54 to 57. Although its configuration differs in some aspects, reference must be made to U.S. Pat. No. 5,183,404.
In FIG. 54, a retractable access portion 37 is provided which is capable of being accommodated within the PC card 1. The modular jack 3A is arranged on the retractable access portion 37 so that the modular plug 2 can be inserted from the direction D substantially orthogonal to major planes of the PC card 1. The major planes referred to here generally comprise two planes occupying the major part of the surface area of the PC card 1. The retractable access portion 37 is inserted into a jack slit 13 formed in one side of the PC card 1 so as to be slidable along the direction C parallel to the major planes. A limiting notch 39 is provided on the surface so as to be able to engage with a lever 12 arranged within the interior of the jack slit 13. It is natural that the positions of the lever 12 and the limiting notch 39 may be reversed. Due to the engagement of the lever 12 with the limiting notch 39, the retractable access portion 37 is positionally fixed at the time of using the modular jack 3A. Within the internal space of the jack slit 13, that is, a jack chamber 14, there may be arranged a spring or the like for saving the labor of protraction and retraction of the retractable access portion 37.
The modular jack 3A further includes a straight aperture 310 formed in the retractable access portion 37 along the direction D. It is to be noted that U.S. Pat. No. 5,183,404 employs an angled aperture in place of the straight aperture. The contact wirings 31 are arranged within the interior of the straight aperture 310. The shape and dimension of the straight aperture 310 are determined so as to be able to apply an inserting direction regulation function, insertion stopping function and returning prevention function. The straight aperture 310 is provided in such a manner as to be exposed to the exterior of the PC card 1 in the state where the lever 12 is engaged with the limiting notch 39, in other words, so as to be able to receive the modular plug 2. Although in FIG. 55 the straight aperture 310 passes through the retractable access portion 37, a blind aperture may be employed as long as the retractable access portion 37 has a sufficient thickness. It is to be appreciated that depending on the position of the retention ridge 36 within the straight aperture 310, the tip of the modular plug 2 may protrude to the back of the retractable access portion 37 as shown in FIG. 56, or it may not protrude thereto as shown in FIG. 57.
According to the improved modular jack 3A, some of the problems entailed in the general structure shown in FIG. 46 can be solved. Firstly, the improved modular jack 3A does not include the integrated connector 11 which may otherwise obstruct the insertion of the memory card 4 into the adjacent slot. Accordingly, in the situation where the retractable access portion 37 is accommodated in the jack chamber 14, the memory card 4 can be inserted into the adjacent slot more easily than the general structure. Secondly, when moving the station with the modular plug 2 removed from the modular jack 3A, a mere accommodation of the retractable access portion 37 into the jack chamber 14 would prevent the PC card from impinging on the desk or the like. Thus, it is difficult for damage to the PC card 1 to occur. Thirdly, because there is no necessity to provide the integrated connector 11, the production and sales costs can be reduced, due to the simplified manufacturing processes, as well as material cost, and space for storing the products.
Nevertheless, the improved modular jack 3A has some problems. Firstly, the modular plug must be inserted into the straight aperture 310 along the direction substantially orthogonal to the major planes, which is a troublesome task. Secondly, in case of the use in an upside-down posture relative to FIGS. 56 and 57, the modular plug 2 and the cord 21 may conflict with other objects (e.g., a desk or other cards). That is, if it is applied to the PC card 1, another object conflicting therewith, or a casing of the station, stable actions of the PC card 1, another card, or the station could not be secured. Thirdly, since the modular plug 2 and the cord 21 protrude in the direction substantially orthogonal to the major planes, the modular plug must be removed prior to the insertion of, e.g., the memory card 4 into the adjacent slot, depending on the setting of the inserting direction of the modular plug 2. Fourthly since the cord 21 extends from the modular plug 2 in the direction substantially orthogonal to the major planes, the cord 21 may possibly become entangled with other cords, or conflict with other cards. Fifthly, the contact wirings 31 must be long enough to ensure a sufficient contact length between the contact wirings 31 and the contact pins 23, and hence the retractable access portion 37 must be thick enough, thus resulting in the reduction of the degree of freedom in designing the retractable access portion 37.